1. Technical Field
Exemplary aspects of the present disclosure generally relate to an image forming apparatus, such as a copier, a facsimile machine, a printer, or a multi-functional system including a combination thereof.
2. Description of the Related Art
Known color image forming apparatuses include tandem-type image forming apparatuses in which toner images of different colors, also known as visible images, are formed on a plurality of latent image bearing members (which may, for example, be photosensitive drums) for different colors arranged in tandem along an intermediate transfer member or a sheet conveyer in its moving direction and superimposed one atop the other, thereby forming a color image. Around each of the latent image bearing members, imaging devices such as a charging device for charging the surface of the latent image bearing member, a writing head for illuminating the surface thereof to form a latent image, a developing device for developing the latent image, and so forth are disposed.
Image forming apparatuses of this kind include a type equipped with a plurality of writing heads held by a movable top cover of the image forming apparatus. The top cover serves as a holder for holding the plurality of the writing heads and is rotatably movable about a shaft provided at one end thereof in the direction in which the plurality of the latent image bearing members are arranged. The top cover covers the upper portion of the image forming apparatus, and with the top cover closed the plurality of the writing heads is positioned at an engaged position at which the writing heads form latent images on the surface of the latent image bearing members. When the top cover is opened, the plurality of the writing heads move together with the top cover, moving from the engaged position to a retracted position.
Moving the writing heads to the retracted position allows image forming units each equipped with the latent image bearing member, the charging device, and the developing device to be removed vertically. The image forming units can be taken out from an upper opening opened by the upper cover.
With reference to FIGS. 10A and 10B, a description is provided of a known image forming apparatus with a movable cover. FIG. 10A is a schematic diagram illustrating a conventional image forming apparatus with a top cover 500 closed. FIG. 10B is a schematic diagram illustrating the conventional image forming apparatus with the top cover 500 opened when removing image forming units 300Y, 300M, 300C, and 300K.
As illustrated in FIG. 10A, in the image forming apparatus, a middle cover 410 which holds each of writing heads 700Y, 700M, 700C, and 700K is rotatably attached to a shaft 510 to which the top cover 500 is also rotatably attached. More specifically, the writing heads 700Y, 700M, 700C, and 700K are rotatably attached to one end of each of arms 760Y, 760M, 760C, and 760K, respectively. The other end of each of the arms 760Y, 760M, 760C, and 760K is pivotally attached to the middle cover 410. The middle cover 410 also holds toner cartridges 130Y, 130M, 130C, and 130K storing toner. As the top cover 500 and the middle cover 410 are moved in the counterclockwise direction in FIG. 10A, the upper portion of a housing 900 of the image forming apparatus is opened, allowing image forming units 300Y, 300M, 300C, and 300K to be removed therefrom.
If the left side of the image forming apparatus (i.e., at a fulcrum side of the top cover 500, that is, the shaft 510 side) is a wall and/or an object with a height higher than that of the image forming apparatus is disposed at the left side, the top cover 500 and the middle cover 410 cannot rotate more than 90 degrees as illustrated in FIG. 10B.
In FIG. 10B, an area T indicated by a double-headed arrow refers to an area in which the image forming unit 300K passes when the image forming unit 300K disposed at the fulcrum side of the middle cover 410 (the left hand side in FIG. 10B) is installed and removed from the housing 900. As illustrated in FIG. 10B, if the top cover 500 and the middle cover 410 are not allowed to turn more than 90 degrees, the writing head 700K at the fulcrum side of the middle cover 410 enters the area T. As a result, when removing the image forming unit 300K from the housing 900, the image forming unit 300K contacts and may damage the writing head 700K.
In view of the above, there is an unsolved need for an image forming apparatus which allows components to be removed therefrom without contacting imaging devices.